System and process for the production of UAN
AssigneeStamicarbon B.V.
InventorStefano Cicchinelli
Life of this patent
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Abstract
Disclosed is a system for the production of urea ammonium nitrate (UAN), which is particularly suitable for processing relatively small ammonium nitrate waste streams into UAN. The system comprises a concentration for ammonium nitrate, a treatment section which allows recovering and recirculating nitrogen compounds entrained in vapor from the concentration section, and a pH control section allowing to adjust the pH of the processed ammonium nitrate waste stream to the extent necessary.
Claims20
A process for the production of urea ammonium nitrate (UAN), comprising obtaining an acid aqueous ammonium nitrate stream resulting as a used scrubbing liquid from subjecting an ammonia-containing off-gas to contact with nitric acid in a scrubber;
- subjecting the acid aqueous ammonium nitrate stream to a pH controlling step, said pH controlling step comprising determining pH and adjusting pH to the extent necessary so as to be within a range of 2 to 4.5 so as to provide a pH-controlled liquid, subjecting said pH-controlled liquid to evaporation so as to obtain a concentrated ammonium nitrate solution and combining said concentrated ammonium nitrate solution and an aqueous urea solution and/or a urea melt so as to obtain a urea ammonium nitrate solution, wherein the acid aqueous ammonium nitrate stream comprises:
- 5-20 wt. % of ammonium nitrate;
- less than 5 wt. % urea, and
- 0.1-0.5 wt. % nitric acid.
Dependencies are inferred from the claim text.